RLx02

Recently the car's been vibrating more than usual when I come to a stop when I'm drive. When I put it in park or in neutral the vibrations go away...causes?

Motor mounts going bad?

doom239

Might be time to check all the fluids. might need a tune up soon.

saer1one

sounds like motor mounts.. have somebody apply the brake, put transmission on reverse and step on the gas, you visually look at the motor, you will be able to tell what side the mount is bad on. you will see motor jump around more than usual.

RLx02

I had an oil change 2k ago and tranny flush about 10k ago.



That's what I'm going to do tomorrow morning...talked to another friend and did some research and motor mounts are prime suspect considering people had theirs go at 40-50k or so.

loudandheard

How bad is your vibration? I feel some vibration every now and then, but it's not severe. I was looking at changing out my motor mounts while I was under the car. Does any one have a part number for the mounts and a diy? Are there any motor mounts that are better than the ones from factory. I remember hearing about some one producing good motor mounts for our cars.

60n5pt1

I've read somewhere in the forum that R&R of the motor mounts parts are costly and labor intensive.

FrankW

engine mount or tranny mount.

91RS

I think mine have gone wrong again, I'm getting the same vibration when stopped. I was told they were already replaced once under warranty before I got the car!

ohfiveC55

New C55 owner here wondering if anyone else finds that putting the car in neutral while stopped smooths the idle and reduces engine shake? I'm sure there are two schools of thought as to whether this is a good or bad practice to begin with, but the car seems to like being neutral while at stop lights...

And for the record, this is BY FAR the most enjoyable, rewarding, understated car I've ever owned. Simply outstanding. Couldn't be happier!

Cheers

saer1one

Whats the mileage on your car if you dont mind..?

91RS

36k

Viper98912

its supposed to, when youre in park or neutral the transmission is disengaged. when on drive but stopped, the transmission is engaged but the brakes are overpowering the small power transfer by the torque converter (hence why the car creeps if you let off the brake)

ruben65

91RS do you drive or accelerate hard on the car constantly? If so that could cause them to wear out faster than they are designed to last.

The motor mounts are designed to last approx 30k-40k miles, so if they were just recently replaced and you don't drive the car hard constantly, I would have it looked at especially if you have warranty.

It could also be from a collapsed transmission mount, those happen more often than the motor mounts it seems... also another thing to check is the drive shaft flex disc, although that is rarely the problem is is always good to check while the car is up in the air.

Let us know the outcome.

91RS

Hah! I drive my car like it says AMG on the back! Why in the world someone would design a mount to last 30-40k miles is just asinine, especially on a high performance vehicle. I was told my trans mount was also replaced. I'm going to complain about the vibration and it looks like I still have an oil leak before my CPO goes out on October. Even the domestics can design a damn motor mount that lasts.

ruben65

Yea I agree its pretty dumb, I have a had a few different Mercedes models over the years from just the regular models to the AMG models and its all the same story with each one on the motor mounts, transmission mounts every time, and around the same mileage every time.

The reason being is because our motor mounts have some sort of gel injected in them, and as the rubber wears out and it starts to slowly leak out, thats when you start getting the vibrations. Other domestic car manufacturers are just solid rubber for the most part, and takes longer to feel the vibration cause there is no gel to leak out.

Also usually around 60k or so the front suspension bushings wear out and need to be replaced also, you'll know cause when you brake the cars front end will shake, or feel like something is loose when going over bumps in the front suspension. Just depends how hard you drive and treat the suspension, you can get longer.

See picture and illustrations below of motor mounts.

Detail of the inside of the motor mount: - the yellow part in the illustration is the gel.


New motor mount Vs. one that has leaked and worn out:

ohfiveC55

Looks like there's a recent and somewhat detailed discussion on this very topic. Could be motor mounts. Yikes.

https://mbworld.org/forums/c32-amg-c...ped-drive.html

JonMBZ

could be a few things, plugs wires engine mounts whats your mileage

RLx02

yeah my bushings are already gone; replaced passenger side but haven't gotten to my driver side. I only have 52k on my car but i have taken it to track days and i drive "spiritedly" whenever its nice

91RS

My Trailblazer has the "oil injected" mounts with 104k on them. No vibrations. I'm trying to get the bushings replaced too, I complained about it once and they said they weren't bad enough yet or something. Hopefully I can at least get the first set replaced before I'm out of warranty. I suppose in the grand scheme of things if mounts and bushings are all that goes wrong in the time I own this car, I'll be happy. If I end up having to replace the bushings myself I'll probably just replace the whole arm that way I get new balljoints too. At this point I shouldn't have a problem getting the mount(s) replaced since there is no denying the problem is there.